By far the most common form of pulmonary embolism is a thromboembolism, which occurs when a blood clot, generally a venous thrombus, becomes dislodged from its site of formation and embolizes to the arterial blood supply of one of the lungs. Symptoms may include difficulty breathing, pain during breathing, and more rarely circulatory instability and death. Treatment is with anticoagulant medication, such as warfarin. Other rarer forms of pulmonary embolism occur when material other than a blood clot is responsible. Such materials can include fat or bone (usually in association with significant trauma), air (often when diving), and amniotic fluid (affecting mothers during child-birth).
Signs of PE are sudden-onset dyspnea (shortness of breath, 73%), tachypnea (rapid breathing, 70%), chest pain of "pleuritic" nature (worsened by breathing, 66%), cough (37%), hemoptysis (coughing up blood, 13%), and in severe cases, cyanosis, tachycardia (rapid heart rate), hypotension, shock, loss of consciousness, and death. Although most cases have no clinical evidence of deep venous thrombosis (DVT) in the legs, findings that indicate DVT may aid in the diagnosis.
Acutely, supportive treatments, such as oxygen or analgesia, are often required.
Massive PE causing hemodynamic instability (marked decreased oxygen saturation, tachycardia and/or hypotension) is an indication for thrombolysis, the enzymatic destruction of the clot with medication. Some advocate its use also if right ventricular dysfunction can be demonstrated on echocardiography.